This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A138403 #23 Mar 31 2025 14:23:16
%S A138403 8,54,500,2058,13310,26364,78608,123462,267674,682892,893730,1823508,
%T A138403 2756840,3339294,4775858,7741604,11911982,13618860,19850358,25053770,
%U A138403 28009224,38457042,46886534,62037272,87616608,103030100,111458154
%N A138403 a(n) = p^3*(p-1), where p = prime(n).
%H A138403 Vincenzo Librandi, <a href="/A138403/b138403.txt">Table of n, a(n) for n = 1..200</a>
%H A138403 <a href="/index/Pri#prime_powers">Index to sequences related to prime powers</a>.
%F A138403 a(n) = A000010(prime(n)^4). - _R. J. Mathar_, Oct 15 2017
%F A138403 From _Amiram Eldar_, Nov 22 2022: (Start)
%F A138403 a(n) = prime(n)^4 - prime(n)^3 = A030514(n) - A030078(n).
%F A138403 Product_{n>=1} (1 - 1/a(n)) = A065415. (End)
%F A138403 Sum_{n>=1} 1/a(n) = A382551. - _R. J. Mathar_, Mar 31 2025
%t A138403 a = {}; Do[p = Prime[n]; AppendTo[a, p^4 - p^3], {n, 1, 50}]; a
%o A138403 (PARI) forprime(p=2,1e3,print1(p^4-p^3", ")) \\ _Charles R Greathouse IV_, Jun 16 2011
%o A138403 (Magma) [NthPrime((n))^4 - NthPrime((n))^3: n in [1..40] ]; // _Vincenzo Librandi_, Jun 17 2011
%Y A138403 Cf. A000010, A030514, A030078, A065415.
%K A138403 nonn,easy
%O A138403 1,1
%A A138403 _Artur Jasinski_, Mar 19 2008